The goal of this study is to establish the mechanism(s) of progression of primarily spinal syringomyelia (PSS). Our preliminary study of syringomyelia emphasized syringomyelia associated with craniocervical junction abnormalities (CCJAS), such as the Chiari I malformation. This new protocol will expand the scope of our investigation to include primarily spinal syringomyelia (PSS), which is defined as syringomyelia not associated with craniocervical junction abnormalities (CCJAS). Etiologies of primarily spinal syringomyelia include 1) intradural scarring which is post-traumatic, post-inflammatory, or post-operative, 2) intradural-extramedullary masses such as arachnoid cysts or meningiomas, and 3) extramedullary-extradural spinal lesions such as cervical spondylosis or spinal deformity.